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differently— more realistically— than 2- D already makes them
an invaluable stand- in for tests and models. Part of the reason
for so many billions being wasted in current pharmaceutical creation
is that the current preclinical models such as dish culture
and mice make poor substitutes for humans. “ There’s a way to
test drugs on human liver cells, but there’s no way to test drugs
on a human liver ,” Organovo’s Mike Renard says. He believes
3- D printing can close that gap, and he’s not alone. Organovo
has already landed partnerships with various pharmaceutical
companies, including Pfizer and United Therapeutics.
It’s the same for cancer research. This January, the Knight
Cancer Institute at Oregon Health and Science University also
inked a deal of its own with Organovo and began building 3- D
models of breast and pancreatic cancers. Here again, printed
cultures are more lifelike: tumor cells are more resistant to
therapy, they migrate extensively, and they communicate more
accurately with cells around them. “ It’s really amazing, the
cells are behaving like aggressive cancer tissue,” says Knight
researcher Rosalie Sears ( Figure 10). Her team is already talking
about a clinical trial with pancreatic cancer patients to see
if they can use this technology to predict a better course of
treatment based on how printed models of the patients’ tumors
respond in vitro ( Figure 11). “ I am really excited,” Sears says. “ I
think this is transformative. It’ll allow us to learn things we’ve
never learned before about tumor cell interactions.”
Printers can craft diseased tissue just as well as healthy, and
that too will most likely be more realistic than a petri dish or a
mouse. Last year at MIT and Harvard Medical School, researchers
printed blocks of neurons that extended their axons and
bore traces of key neurotransmitters— a proof- of- concept the
researchers there hope could become models for normal and disordered
processes in the brain.
And yes, organs too will eventually emerge. Even the pragmatists
who worry over the field’s inevitable clash with regulatory
bodies and clinical standards are confident in this. “ We’ll
see movement on that within a decade,” says David Williams, a
manufacturing and regulatory scientist at Loughborough University,
United Kingdom, who has been tracking the bioprinting
industry’s emergence with an eye for its future hurdles. It won’t
be the livers or the kidneys, he says, but it will be the simpler
things, parts that don’t require a lot of vascularization or different
types of tissues— bone, for instance. Others, like Derby, predict
that cartilage and skin will emerge as early players on the scene
as well and for the same reasons. Then most likely will come partial
organs that sidestep complexity, like faux pancreases made of
membranes, basic insulin- producing cells, and very little else.
“ It’s something that we’ll have happen in the next generation,”
Williams says. “ The energy of the community will make it happen.”
Shannon Fischer is a freelance science writer living in Boston, Massachusetts.
For Further Reading
T. Boland, V. Mironov, A. Gutowska, E. A. Roth, and R. R. Markwald,
“ Cell and organ printing 2: Fusion of cell aggregates in three- dimensional
gels,” Anat. Rec. A, vol. 272A, no. 2, pp. 497– 502, June 2003.
B. Derby, “ Printing and prototyping of tissues and scaffolds,” Science ,
vol. 338, no. 6109, pp. 921– 926, Nov. 2012.
C. J. Ferris, K. G. Gilmore, G. G. Wallace, and M. in het Panhuis,
“ Biofabrication: An overview of the approaches used for printing of living
cells,” Appl. Microbiol. Biotechnol. , vol. 97, no. 10, pp. 4243– 4258, 2013.
K. Jakab, C. Norotte, F. Marga, K. Murphy, G. Vunjak- Novakovic,
and G. Forgacs, “ Tissue engineering by self- assembly and bio- printing
of living cells,” Biofabrication , vol. 2, no. 2, p. 022001, 2010.
R. J. Klebe, “ Cytoscribing: A method for micropositioning cells
and the construction of two- and three- dimensional synthetic tissues,”
Exp. Cell Res. , vol. 179, no. 2, pp. 362– 373, Dec. 1988.
F. P. W. Melchels, M. A. N. Domingos, T. J. Klein, J. Malda, P. J.
Bartolo, and D. W. Hutmacher, “ Additive manufacturing of tissues and
organs,” Prog. Polym. Sci., vol. 37, no. 8, pp. 1079– 1104, Aug. 2012.
I. T. Ozbolat and Y. Yu, “ Bioprinting towards organ fabrication:
Challenges and future trends,” IEEE Trans. Biomed. Eng. , vol. 60,
no. 3, pp. 1– 9, 2013.
J. P. Vacanti, M. A. Morse, W. M. Saltzman, A. J. Domb, A. Perez-
Atayde, and R. Langer, “ Selective cell transplantation using bioabsorbable
artificial polymers as matrices,” J. Pediatr. Surg., vol. 123, no. 1,
pp. 3– 9, 1988.
W. C. Wilson and T. Boland, “ Cell and organ printing 1: Protein and
cell printers,” Anat. Rec. A, vol. 272A, no. 2, pp. 491– 496, June 2003.
FIGURE 10 Rosalie Sears, a researcher at the Oregon Health
and Science University Knight Cancer Institute, is working
with Organovo to develop 3- D printed tumor models. ( Photo
courtesy of Carl Pelz.)
FIGURE 11 Sears oversees Ellen Langer, a senior postdoctoral
fellow, who pipettes cells and media into tissue culture plates
to grow for future studies, including bioprinting and drug
treatment. ( Photo courtesy of Carl Pelz.)